This invention relates generally to O-ring sealing methods and apparatus, utilized for example in the completion of hydrocarbon wells. The invention is particularly directed to methods of such O-ring use, for contributing inter alia to reducing the amount of drillrig time and associated expense associated with hanging casing or tubing within a previously installed concentric outer casing.
There is need for improvements in apparatus and method for installing casing strings in oil and gas wells, and which reduce time and cost of such installation.